Catica is correct, designer fruit is square/pyramid-shaped watermelons, apples with messages reverse-stenciled onto them by strategically blocking the sun, $200 bunches of grapes the size of golf balls, etc.
We don't buy those. "Designer fruit" is our tongue-in-cheek way of saying we don't mind shelling out for Japanese fruit, which is quite high quality even if it's not custom shaped or what have you. Even "normal" Japanese fruit is expensive; there are not really any cheap options. For example, we're ecstatic to get apples for $1 each (online, in bulk, directly from the growers, misshapen or nicked or with other defects but the same great taste), but usually pay around $1.25 and as much as $1.75 at the store. These aren't gritty, sandy Red Delicious apples the size of baseballs--they're fujis or other variants at least the size of a large person's fist.
We prioritize taste and buying domestic when possible; it's not about the nutritional value at all (I'd be surprised if the nutritional value were any different). Imported fruit doesn't look very good, isn't abundantly stocked, and often isn't any cheaper, so we nearly always go with Japanese.